10:45 AM - 11:00 AM
[PEM12-06] Simulation of atmosphere-ionosphere variations associated with the eruption of the Tonga volcano on 15 January 2022
Keywords:Tonga, volcano, eruption, atmosphere, ionosphere, simulation
On 15 January 2022 significant variations in the ionosphere and the atmosphere were observed worldwide, which is clearly associated with the eruption of Hunga Tonga-Hunga Ha'apai in Tonga. In this event, various kinds of phenomena have been reported: (1) atmospheric waves such as acoustic-gravity waves, Lamb waves, and Pekeris waves, (2) significant depletion of TEC near the eruption site, (3) oscillations in TEC and geomagnetic field with a period of several minutes, (4) occurrence of equatorial plasma bubbles, (5) TIDs (traveling ionospheric disturbances) concentrically propagating from the eruption site, (6) variations in TEC/geomagnetic field in the magnetic conjugates. To reproduce atmospheric-ionospheric disturbances driven by the eruption of the volcano, we employed the whole atmosphere-ionosphere coupled model GAIA and an axisymmetric 3-D nonhydrostatic atmospheric model. In this simulation, a sudden temperature change in the eruption point is given to the nonhydrostatic atmospheric model, and then the calculated neutral wind variations are incorporated into GAIA to simulate ionospheric variations driven by the eruption. We found that the simulation can produce various kinds of atmospheric waves generated by the eruption, TEC variations with a period of several minutes, and TIDs concentrically propagating from the eruption site as well as TEC variations in the magnetically conjugate ionosphere. Some of the results agree with the observations fairly well. The result also shows that the ionosphere tends to become more unstable in the evening region, which is likely to lead to generation of equatorial plasma bubbles. We will present the results of the simulation and discuss the physical processes of those phenomena.